When you were young, your mother got tired of changing your diaper every time that you pissed and she trained you to only piss when you were on the potty. Usually, this was a pot, about the size of one of her cooking pots, and just about as big. And, every time that you successfully made it to the pot to piss instead of using a diaper there was a celebration - for a while.
And then you became a slave to the toilet. When your bladder got full, this became the upper most consideration in your life - to find a socially acceptable place to empty it. How many times have you been on a trip and you've driven like a mad man to find a socially acceptable place to piss and find relief from your overfull bladder? How many times have you interrupted a movie or TV show because your bladder was full? How many times have you had to stop work on an important project because you couldn't wait any longer to go and piss?
Wearing a diaper and using that helps, but you still have to deal with the urges to piss and the need to satisfy them. You want to eliminate this controlling part of your life. You want the piss to flow out of your bladder as it is ready, just like it did before your mother worked so hard to potty train you.

BASIC #1:  This can not be a 'sometimes' thing. If you want to be truly incontinent, then you need to be incontinent all of the time. This means that you must wear a diaper all of the time. The ONLY  time that you don't wear a diaper is when you are showering.
Make sure that you use a diaper that fits you well and is comfortable. Different people's lower torsos are shaped differently. And, different diapers are 'cut' differently. Each one is going to fit you differently. Find the one that fits you the best. A good diaper has leg elastics and guards that will make an effective seal around your legs so that the piss does not leak out of the diaper. The diaper needs to fit you comfortably and not cause sore spots.

BASIC #2:  You have spent many years controlling your pee and your poop. It is a learned skill that you learned when you were a small child - probably. Just as you learned how to control them, you now have to learn how to 'uncontrol' them. It took practice to gain control. It will take practice to lose control.
A lot of this depends on MANY factors. How early you were potty trained; how easy it is for you to relax your pee control muscles; how deeply you sleep; etc. How long you regularly had to hold it before you could get to a socially acceptable place to empty your bladder. It takes a LOT of work to undo what your mother spent a long time training you to do! :-)
This is a 'mind over matter' thing. You are going to change some of your habits. You are going to teach your mind a different way to deal with your need to eliminate piss from your body.
You are going to play mind games. You are going to play a game with your own mind. You are going to make your own mind believe that it's all right to piss anytime that it gets the signal from your sphincter muscles that it needs to be emptied. Once it gets that signal it will send out the signal to the control muscles to relax and open up.

ANATOMY 101:  There are two kidneys up inside your body that filter impurities out of your blood. They also soak up the excess liquid in your body and they convert all of this to pee and send it to your bladder. Your bladder is nestled at the very bottom of your torso. To find it, right over your penis or your vagina, if you press down hard, you will feel the bone that is your pelvis. Your bladder is right behind this bone. If you bring your fingers up just a little toward your belly button, the bone ends and you can feel the top of the bladder.
At the bottom of the bladder, way at the bottom of your torso, is the outlet of the bladder, and this is controlled by the sphincter muscles. It is this pair of muscles that have the control over whether you are continent, or not. They are controlled by the nerves that travel from the brain, down the spinal column and then to the sphincter. These muscles are well protected by the bone of the pelvis. There is no way that you can reach them from outside of the body to disable them without doing some serious surgery. And, no medical person that wants to keep their license is going to go in there with a knife for the purpose of making a person incontinent.
Since this sphincter is the one that is exercising the control that we want to get rid of, the only option that we have is to train it to behave differently.

IMPORTANT RULES:

#1:  Always, always wear a diaper, all day, all night, all of the time.
#2:  Never, never, never pee into anything that is not a diaper.
#3:  Always keep your pubic area completely free of all hair.

The goal is to get the sphincter muscle so that it is totally relaxed all of the time. Totally relaxed and letting the bladder empty itself naturally. You also have to get your mind trained to ignore your bladder and it's sphincter muscle.

Work on being able to pee while you are walking down the street, without missing a beat.

If you are sitting in class at school, practice relaxing your sphincter muscle, even if you don't feel the need to pee.

If you are at work, just let your sub-conscious take over and relax the muscle and let the pee come out.

After you have emptied your bladder, note how relaxed the sphincter muscle is. Work on keeping that relaxed feeling for as long as you can.

Drink lots of plain water during the day. Your body needs a lot of water, at least 8 ounces of water or juice at least 8 times a day. Avoid alcohol while you are learning. "What goes in must come out". Plain water will act as a mild diuretic and you will have to piss more often. It also flushes out your body and removes toxins and other bad things. Because this makes you piss more often it speeds up the un-training process.

Do NOT force the pee to come out. If only a little wants to come out, that's just fine. Don't push it. Let it flow naturally. If you try to force the piss to come out you are exercising the muscles that you are trying to weaken.

While the pee is coming out make a conscious note to yourself about how good it feels, and how much you like it. Congratulate yourself for having done this.

For some/most people, within 7-10 days you are going to be finding yourself with a wet diaper and you won't realize that it happened until it is all over. This marks the start of your conversion and tells you that you are on the right track and that you are making progress. This is not complete incontinence, it's only the first sign that you are adapting. With each passing day you will experience this sensation more and more. It may be several weeks before your un-training is complete.

At night, put on a fresh diaper. As you are going to sleep, keep telling yourself that it's all right to pee without waking up. Do that every night. If you do wake up in the night having to pee, roll into whatever position is easiest for you to pee in while you are in bed, and let it go - trying to not wake up any more than you have to. Then drop back off to sleep. This can take up to several weeks for it to be effective. (It may take MANY nights to figure out the best position for peeing while you are in bed. The proper position is VERY important for many people!)

A lot of this depends on MANY factors. How early you were potty trained; how easy it is for you to relax your piss control muscles; how deeply you sleep; etc. It takes a LOT of work to undo what your mother spent a long time training you to do! :-)

When you are laying in bed, try various positions. On your back, on your stomach, as well as trying both sides. Sometimes it's a matter of getting those control muscles shifted just right inside your body. Try it with your legs straight out. Try it with your knees bent.

You may be trying too hard, too.

You might try getting some drugs at the store that will make you sleep more soundly. Melatonin is good. Benadryl is good. And, there are other over-the-counter drugs being sold specifically for making you sleep. The idea here is to get you so relaxed and so sound asleep that you will sleep through it. However, you may be quite groggy the next day after you take anything to make you sleep, especially if you increase the quantity above the recommended dosage (which you may well have to do to get the level of sleep you need to lose control).

Drinks with caffeine are going to tend to keep you awake and more alert. During this initial phase of trying to get started, I recommend that you avoid beverages containing caffeine. OTOH, caffeine will act like a diuretic for most people. When you are at the drug store, find some diuretic pills that don't contain caffeine, and try taking some of those before you go to bed.

NOTE: I have NO idea of how safe, or dangerous, it is to combine those various drugs. Especially when you are using quantities in excess of the recommended dosage.

Before you go to bed, wet your diaper a little. I am told by several people that once they have a wet diaper on that it's a lot easier to piss the next time. (It's all a mind game!)

As you drop off to sleep keep telling your sub-conscious that it's all right to wet the bed. This is a form of self-hypnosis and in the few moments before you fall into a complete sleep your brain is very susceptible to these thoughts. As you rouse up in the night with the need to pee, imagine that you are standing in front of the toilet peeing.

It may take many nights of trying these steps before you have success.
 

NOTE: I have made several suggestions about things that you can eat, drink, or otherwise swallow to assist you with your un-training. If you choose to follow any of these suggestions, you do so at your own risk. There is an inherent risk every time that you take something inside of your body. Mixing various things that are supposedly safe can be dangerous. (Aspirin and Ibuprofin don't mix, for example.) In some cases, you may have to take a bigger dose than the manufacturer recommends. This can be dangerous, or it can be very effective.

QUESTIONS? Ask Big Daddy